Exhibit 99.1




                              FOR IMMEDIATE RELEASE



Investors:                                      Media:
Emer Reynolds                                   Anita Kawatra
Ph:  353-1-709-4000                             Ph:  212-407-5755
     800-252-3526                                    800-252-3526


            ELAN ACHIEVES PRIMARY ENDPOINT IN PRIALT PHASE III TRIAL

 Amendment to New Drug Application expected to be filed with U.S. Food and Drug
                        Administration in second quarter


DUBLIN, IRELAND, JANUARY 7, 2004 --Elan Corporation, plc today announced that
its recent Phase III trial for Prialt(TM) (ziconotide) met its primary endpoint
in patients with severe chronic pain who had not achieved pain relief with other
therapies including intrathecally delivered morphine. In the double-blind,
placebo-controlled study, patients taking Prialt achieved statistically
significant improvement at Week 3 in the Visual Analog Scale of Pain Intensity
(VASPI) score, the most commonly used pain assessment scale for clinical trials.
In the company's analysis, the treatment appears to be safe, efficacious, and
well tolerated. Based on the positive results, the company expects to file an
amendment to its New Drug Application (NDA) with the U.S. Food and Drug
Administration (FDA) in the second quarter of 2004 and to bring the treatment to
market no later than the first quarter of 2005.

Prialt is the first in a new class of non-opioid analgesics known as N-type
calcium channel blockers, administered intrathecally for the treatment of severe
chronic pain. Elan submitted an application for approval for marketing Prialt in
the European Union in May 2003.

Dr. Lars Ekman, executive vice president and president, Research & Development,
Elan, said, "We are very encouraged by these definitive findings with Prialt and
believe that this is significant news for patients suffering with severe chronic
pain, many of whom are not now adequately treated. This study fulfills the
clinical requirement in response to the FDA's previous



Elan Achieves Primary Endpoint in Prialt Phase III Trial
Page 2


approvable letter, and upon submission, we anticipate a six month review for the
amendment to the NDA."

The FDA had previously issued an approvable letter for Prialt, in which the
agency had requested additional information. This trial was conducted in
response to the FDA's clinical request and designed with their input, studying
220 patients with severe chronic pain to demonstrate the efficacy and safety of
lower doses of Prialt and a slower titration schedule than was used in two
previous Phase III studies. In this clinical trial, there were few serious side
effects, with an incidence similar to placebo. These data will be presented at a
major scientific pain meeting this year.

As a non-opioid analgesic for patients with severe chronic pain such as
neuropathic pain or pain secondary to cancer, Prialt addresses a significant
unmet medical need. About two million patients in the U.S. with chronic pain
fail to respond to existing comprehensive treatment. Of these, about 300,000 may
be considered as potential candidates for intrathecal treatment, which could
include Prialt. In order to make this treatment available to patients during the
review process, a Treatment IND to make Prialt available on a limited basis to
select pain centres in the United States will begin in the first quarter of
2004.

About Elan

Elan is focused on the discovery, development, manufacturing, sale and marketing
of novel therapeutic products in neurology, severe pain and autoimmune diseases.
Elan (NYSE: ELN) shares trade on the New York, London and Dublin Stock
Exchanges.


This document contains forward-looking statements about Elan's business
prospects, including the receipt of regulatory approval for and the launch of
Prialt, that involve substantial risks and uncertainties. You can identify these
statements by the fact that they use words such as "anticipate", "expect, "
"estimate", "project", "intend", "plan", "believe" and other words and terms of
similar meaning in connection with any discussion of future operating or
financial performance or events. Among the factors that could cause actual
results to differ materially from those described herein are the following: the
timing and outcome of the FDA's review of the Prialt NDA amendment; Elan's
ability to effectively commercialize Prialt on a timely basis; the outcome of
the ongoing SEC investigation and the shareholder and other pending litigation;
the outcome of Elan's recovery plan and its ability to maintain flexibility and
maintain sufficient cash, liquid resources, and investments and other assets
capable of being monetized to meet its liquidity requirements; the success of
Elan's other research and development activities and the speed with which
regulatory authorizations and product launches may be achieved; competitive
developments affecting Elan's current products and products under development,
including Prialt; the ability to successfully market both new and existing
products; difficulties or delays in manufacturing; the ability to meet generic
and branded competition after the expiration of Elan's patents; the trend
towards managed care and health care cost containment; possible legislation
affecting pharmaceutical pricing; exposure to product liability and other types
of





Elan Achieves Primary Endpoint in Prialt Phase III Trial
Page 3

lawsuits; Elan's ability to protect its intellectual property; governmental
laws and regulations affecting domestic and foreign operations; growth in costs
and expenses; changes in product mix; and the impact of acquisitions,
divestitures, restructurings, product withdrawals and other unusual items. A
further list and description of these risks, uncertainties and other matters can
be found in Elan's Annual Report on Form 20-F for the fiscal year ended December
31, 2002, and in its Reports of Foreign Issuer on Form 6-K. Elan assumes no
obligation to update any forward-looking statements, whether as a result of new
information, future events or otherwise.